26 research outputs found
Differentiation of embryonic stem cells into functional neurons in vitro
Embryonic stem (ES) cells are pluripotent cells that are derived from the inner cell mass of blastocysts. We produced neuronal cells by directed differentiation of a newly established murine ES cell line in vitro (Royan B1). Immunohistochemistry, scanning electron microscopy, Campenot's assay and electrophysiology were used to evaluate the differentiated neurons. Antibodies against microtubule-associated protein (MAP2), glutamic acid decarboxylase (GAD) and tyrosine hydroxylase (TH) antigens showed that the cells had GABAergic and dopaminergic characteristics. The Campenot's assay revealed there were a number of peripheral nerveous system related neurons but they were rare. The cells also produced action potentials and responded to electrical stimulation by expressing calcium channels in the processes. We showed therefore that functional neurons can be generated by directed differentiation from embryonic stem cells in vitro
Investigation of Mechanical Properties of Metal Inert Gas-Brazed TRIP800 Steel Joints Using Different Shielding Gas Flow Rate
In this study, TRIP 800 (transformation induced plasticity) steel plates having 1.5 mm thickness were joined by copper-based (CuAl8) wire in gas metal arc brazing technique. Specimens were prepared in joining forms as butt joint. Brazing operations were done with five different shielding gas flow rates of 8, 10, 12, 14, and 16 L/min. CuAl8 wire composed mostly of copper serves as the filler metal. Having accomplished the brazing operations, tensile properties of joints were detected, and micro- and macrostructures of joints were investigated in order to see the joinability of TRIP 800 steel by gas metal arc brazing technique
Effect of Welding Current on Mechanical Properties of Welding Joints in S235JR(Cu) Steel Sheets in Resistance Spot Welding
This paper presents an experimental study on resistance spot welding of S235JR(Cu) steel sheets used in side wall and roof in rail vehicles. S235JR(Cu) steel sheets having 2.0 mm thicknesses were joined by using resistance spot welding as lap joint. A timer and current controlled resistance spot welding machine having 120 kVA capacity and a pneumatic application mechanism with a single lever was used to prepare the specimens. Welding periods were chosen as 10, 15, 20, 25 and 30 cycles and also welding currents were increased from 6 kA up to 14 kA by rise of 1 kA. The electrode force was kept constant at 6 kN. The prepared welding specimens were exposed to tensile-shear and tensile-peel tests and the obtained results were supported by diagrams and, finally, appropriate welding parameters were advised to the users
Analysis of factors affecting satisfaction in the emergency department: A survey of 1019 patients
The objective of this study was to identify factors that affect overall satisfaction of patients admitted to the emergency department (ED). All consecutive adult patients in the ED during a 14-day period who could communicate well were enrolled into this cross-sectional analytic study. Patients' demographic data, information on care, and level of satisfaction were recorded. Patients were asked to rate specific issues concerning their satisfaction (good and excellent) on a 5-point Likert scale. Response to the survey was obtained from 1019 (91.6%.) of 1113 patients for analysis during the study. Satisfaction with physician experience, physician attitude, triage, explanation of health status and treatment, and discharge instructions were found to have significant impact on satisfaction (P < .001 for each). Satisfaction with physician experience level was the most important factor affecting overall satisfaction. Patient perception of the total time spent in the ED as "short" and "very short" was not demonstrated to be significantly related to overall satisfaction (P = .162). Temporal perceptions as "long" and "very long" were shown to be significantly related to overall satisfaction (P < .001). Behavioral characteristics of the healthcare providers and the hospital itself were the factors that had the greatest impact on overall satisfaction of the ED population evaluated